Feeding mechanism for blindstitching-machines.



T. J. HAYES. FEEDING MECHANISM FOR BLINDSTITCHING MACHINES.

1,225,628 APPLICATION FILED APR- 9, I914- Patented May 8 3 SHEETS-SHEETI.

WiInesses.

mllltikilfi'lflflswu mama-ma. msuma run. a. c.

T. 1. HAYES. FEEDING MECHANISM FOR BLINDSTITCHING MACHINES.

APP UCAT|0N FILED APR. 9,1914- Patented May 8,1917.

3 SHEETS-SHEET 2.

Fig.2. Fig.3.

Witnesses. Inventor.

Thomas J. Hayes,

I b y m nu: norms Inns co.. rnamuma. vuulfidwmi T. J. HAYES.

FEEDING MECHANISM FOR BLINDSTITCHING MACHINES-I APPLICATION FILED APFLQ,I914.

97 1 a 05 3 m 0 9 3 w V. II 0 3 w H OOH 9 F a? 5 MN 5 A. 1 Y d u .4 0 Huu II| |I t mm 0 t 4 .1 s h v u F Im m 0 by n I; m w m m .I

VII

.n M. MW i l w a w 8% 5 5 2 1m M 6,. I m I i a n0 w 4 m m W W FATE@FFTQ...

THOMAS J. HAYES, OF RO-SLINIDALE, MASSACHUSETTS, ASSIGNOR 'I'O ARBETTERFELL- INGr MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OFMAINE.

FEEDING MECHANISM FOR BLINDSTITCHING-MACHINES.

Specification of Letters latent.

Patented May 8, 1917.

Application filed April 9,1914. Serial No. 830,790.

To all whom it may concern Be it known that I, THoMAs J. HAYEs, acitizen of the United States, and resident of Roslindale, county ofSuffolk, State of Massachusetts, have invented an Improvement in FeedingMechanism for Blindstitching-Machines, of which the followingdescription, in connection with the accompanying drawing, is aspecification, like characters on the drawing representing like parts.

This invention relates to improvements in feeding mechanism for sewingmachines and particularly machinesadapted for blind stitching forfelling in which a curved oscillating needle and complemental stitchforming mechanism are supported above the bed plate and which have meansfor causing the needle to penetrate alternately the base layer of thefabric and the superimposed layer to form two parallel rows of stitcheswhich when drawn taut by the tension of the thread will produce a felledblind seam.

In feeding the material through machines of this character it isnecessary that the superimposed layer of goods be advanced at exactlythe same rate of speed at which the lower or base layer of the fabric isforwarded in order to avoid wrinkling or puckering the goods. Toaccomplish this purpose this invention comprises means for positivelyclamping both layers of the goods between an upper and a lower feed dogand causing the same to be advanced by the movement of the lower feeddog while thus clamped together.

Another object of the invention is to provide an improved means forclamping the work against a stationary overhead presser foot either bythe Work support or the feed dog so that there will be no time in whichthe work is not positively engaged by one or the other of thesemechanisms.

Another object of the invention is to provide improved means foradjusting the extent of forward and backward movement of the dog.

Other objects of the invention will more fully appear from the followingdescription and accompanying drawings and the suboined claims.

In the drawings: Figure 1 1s a horizontal sectional view taken axiallyof the sewing machine arm,

but showing the main shaft of the machine and the cams thereon inelevation,

Fig. 2 is a front view of the head of the sewing machine showing therelation of the upper and lower feed mechanisms,

Fig. 3 is a rear elevation partly broken away to illustrate the meansfor adjusting the feeding mechanism,

Fig. 4 isa detail side elevation of the work support and of the lowerfeeding mechanism and means for actuating the same,

Fig. 5 is a detail front View of the same.

Fig. 6 is a detail plan View of the same showing the connection of thefeeding mechanism to the rock shaft and rocking sleeve whichrespectively cause forward and backward movement of the feed dog and theup and down movement thereof,

Fig. 7 is a median detail sectional view of the work support and feeddog,

Fig. 8 is a detail view of the supporting member for the serrated feeddog, and,

Fig. 9 is a view of the serrated dog.

The preferred form of invention is illustrated herein in connection withan improved stitch forming mechanism for blind stitch sewing machineswhich forms the subject matter of a companion application filed the 9thday of April 1914, Serial Number 880,788.

The sewing machine illustrated comprises the usual bed plate 1 having avertical hollow standard 2 rising therefrom and having a horizontal arm3 extending parallel to the bed plate and terminating in a head acontainingthe needle mechanism and the complemental stitch formingmechanism and the upper feeding mechanism.

The arm 3 is provided at its rear end, its middle portion, and adjacentto the head with bosses 5, 6, and? which contain alined bearings for theshaft 8. The shaft 8 is provided at its rear end vith the usual drivingpulley 9 and hand wheel 10 and is provided throughout its length withthe necessary cams to operate the feed mechanism, the take up and thestitch forming mechanism.

As illustrated in the drawing the needle mechanism comprises a curvedoscillating needle carried by a needle bar 11 which is pivotally mountedto vibrate in the plane inclined to the work supporting surface of thework support in bearings 12 upon the lower end of a supporting member 13which is pivotally mounted upon a shaft 14 journaled in the top of thesewing machine head, means being provided including a link 15 forvibrating the needle support 13 upon its pivotal shaft to produce theshogging movement necessary to form two parallel lines of stitching.

Suitable mechanism, not shown, is provided for oscillating the needle.The complemental stitch forming mechanism preferably comprises a rotaryhook 16, suitably mounted in a hook bracket 17 and driven throughsuitable gearings carried by said bracket from a counter shaft 18 whichhas a gear 19 which meshes with a gear 20 upon the main shaft of themachine. (See Fig. 1.) The hook bracket is desirably pivotally supportedby the shaft 18 so that the hook may be removed laterally from itsnormal position relative to the needle for the purpose of replacing thebobbin. The hook bracket is normally maintained in operative relation tothe needle mechanism by means of a spring pressed. latch 21 whichengages a lug 22 carried by a segmental front plate 23 attached to thehead of the machine. The presser foot 24 preferably is secured rigidlyto a projection 25 on the lower end of the hook bracket so that thepresser foot is maintained in a relatively rigid relation to the bedplate. The goods are clamped against said presser foot plate and are fedforward to produce the line of stitching by the relative movement of thework support and the feed-dog which will hereafter be described.

The lower feeding mechanism is supported upon a U-shaped framepreferably made integral with and depending from the under surface ofthe base plate and comprising vertical portions 26, 27 and horizon talmembers 28 and 29, said horizontal members being provided with alinedbearings. The work support 30 comprises an inverted L-shaped memberhaving a cylindrical sleeve 31 provided with a lateral projection 32providing a seat for a spring 33 which is supported at its lower end ina socket 34 in the cross piece 28 and is provided with an .adjustingscrew 35 adapted to bear upon the end of the spring to regulate thetension thereof. The sleeve 31 surrounds and telescopically supports acylindrical standard 36 having at its upper end a horizontal arm 37provided with an L-shaped member 38 secured thereto by screw 39 toprovide a sliding way for the horizontal web 40 of the feed dog support.

The feed dog support which is shown in detail in Fig. 8 is provided witha pair of parallel. ribs 41, 42. The rib 41 being provided at itsforward end with screw holes 43 to receive screws whereby the feed dog44 may be secured thereto. The feed dog is illustrated in detail in Fig.9 and comprises three united parallel serrated work engaging faces, theintermediate of said faces being shortened and adapted to engage thework immediately in the rear of the needle throat. The web 40 of thefeed dog support is slidably mounted upon the arm 37 beneath the member38 which fits in the channel formed by the web 40 and the ribs 41-42.The dog support is provided with a downwardly extending ear 45 throughwhich the forward and backward movement is imparted to said dog. It willbe obvious that the horizontal member 40 is so guided beneath theoverhanging member 38 that the feed dog will reciprocate in asubstantially horizontal plane in its forward and backward movement.

The work support is provided with the usual work engaging plate havingparallel slots through which the serrated members of the lower feed dogare permitted to proj ect to engage said work, the work engaging platebeing secured to the work support 30 in any suitable manner as by pinsor screws.

In order to provide the forward and backward movement of the dog thedepending ear 45 is pivotally attached to a member 46 having acylindrical stem 47 telescopically arranged within a link 48 which. ispivotally mounted upon a stud 49 projecting laterally from a cross head50 which is secured to the standard 36 by a set screw 51 (see Fig. 5).The link 48 is oscillated about its pivotal support 49 through a link 52which is pivoted to a forward extension 53 of said member 48, theopposite end of the link 52 being connected to the end of an arm 54 of arock shaft 55 which is suitably supported in journals depending from theunder surface of the bed plate and extends to a floating link 56 havingat its upper end a yoke inclosing a cam 57 mounted upon the main shaftof the machine.

The means for adjusting the forward and backward movement of the feeddog preferably comprises a bell crank lever 58 pivoted at its elbow on astud 59 projecting from the inner portion of the standard, one

arm 60 of said bell crank lever being connected at its extremity to alink (not shown) which in turn is connected to the floating link 56. Theother arm of said bell crank lever is provided with an extension 61projecting through a slot 62 in the standard and provided with a milledscrew 63 by which the arm 61 may be clamped in adjusted positions alongthe slot against the arcuate surfaces 64 of the walls of said slot. Bythis construction the position of the movable fulcrum of the floatinglever 56 may be adjusted in respect to the axis of said link to producea greater or less upward and downward movement thereof and consequentlya greater or less oscillation of the rock shaft to determine the extentof forward and backward movement of the feed dog.

In order to provide for a positive clamping action upon the goods at alltimes and thus avoid displacement of the relative positions of'the baselayer and superimposed layer of the fabric I have devised a novel meansfor normally forcing the work support against the under surface of thefabric to clamp it against the presser foot during the stitch formingoperation combined with means whereby the forcing of the feed dog intoengagement with the fabric will cause the withdrawal of the work supportfrom its clamping engagement to permit the advance of the work by thefeed dog. This mechanism in the form of the invention illustrated hereincomprises a toggle mechanism connecting the feed dog support with thework support so that when either the feed dog or the work support is inclamping relation to the presser foot the other mem-' her will bewithdrawn from its clamping engagement.

By this construction it will be obvious that the work will be positivelyclamped during the movement of the needle in its penetrating action toform the stitch and that it will be withdrawn from such clampingposition when the dog rises to clamp the work against the presser footwhile it advances the work for the next succeeding stitch.

The toggle mechanism illustrated in the preferred embodiment of theinvention shown herein comprises a link pivoted upon a stud 66projecting from the end of the cross head 50, the upper end of said linkbeing pivotally connected to a boss 67 substantially in the middle of abell crank lever, one arm of which 68 is pivoted upon a stud 69 securedto the side of the work support 30 the other arm 70 of said lever beingpivotally attached to the end of a link 71 which is pivoted at itsopposite end to an arm 72 projecting from a split collar 73 which may beadjustably secured by a clamping screw 74; upon a sleeve 75 surroundingthe rock shaft The sleeve 7 5 is desirably given a rock ing movement bya link 76 having at its upper end a strap 77 engaging a suitableeccentric 7 8 located upon the main shaft of the machine within thevertical hollow standard 2.

In the operation of the feed dog and the work support the forwardmovement of the link 71 will cause a shortening of the toggle connectionformed by the link 68 and the bell crank lever 70 permitting the worksupport 30 to be forced against the under surface of the cloth to clampthe same upon the stationary presser foot by the spring 33.

During the time the work is thus engaged between the work support andthe presser foot the stitch forming mechanism performs its function ofmaking a stitch either in the superimposed layer or in the base layer asthe case may be. ll hen the stitch has been completed the rocking sleevewill be oscillated in the opposite direction straightening the toggleand causing the feed dog to rise and engage the under surface of thework, clamping the work against the stationary presser foot. Furtherstraightening the toggle causes the downward depression of the worksupport through the cross head 50 and the standard 30 thus removing thework support from its engagement with the under surface of the work. Assoon as the work support has released its engagement with the goods thelink 52 is advanced by the rocking of the shaft 55 causing the member &8to be oscillated upon its pivot 4.9 so that its upper portion willadvance, the telescopic connection between the parts a7 and 48permitting the feed dog to advance in a horizontal plane parallel to thework supporting surface of the work support by reason of the guidingaction of the members 37, 38 upon the horizontal web 40 of the feed dogsupport.

By the construction above described a simple and effective means isprovided for feeding the work through the machine and this feed alonewould be ample for ordinary purposes. I have however found it to bedesirable to provide an upper feed dog to co operate with the lower feeddog in its forward movement in order to insure the simultaneous movementof the superimposed layer of fabric with the base layer of fabric. Thismechanism comprises preferably a walking feed dog adapted to be forceddownward into engagement with the upper surface of the work as the lowerfeed dog rises to engage the under surface of the work. The upper feeddog is thereupon ad vanced by the lower feed in its forward feedingmovement so that the cooperating upper and lower feed dogs moveabsolutely in unison and their amplitude of movement necessarily isexactly the same.

In the preferred embodiment of the invention disclosed herein the upperfeed dog 80 is desirably adjustably secured to the lower end of a link81 which is secured at its upper end to a stud 82 projecting later allyfrom the elbow 83 of a bell crank lever the lower arm 84 of which ispivoted to a stud 85 projecting inwardly from the mental front plate 23the end of the other arm 86 of the said bell crank lever being pivotallyconnected to a link 87 which is pivotally attached at its opposite endto the end of an arm 88 of a rock shaft 89. The rock shaft 89 desirablyis journaled in lugs and 91 projecting laterally from the head and sideof the sewing machine arm, and has on its opposite end an arm 92pivotally connected to a link 93 which has a strap 94: embracing a cam95 on the main shaft. It will be obvious that the oscillation of theshaft 89 by the cam 95 will cause a substantially longitudinalreciprocation of the link 87 which will rock the bell crank lever uponits supporting pivot 85 and thereby cause the elbow thereof to raise andlower in a substantially vertical plane thus raising and lowering thefeed dog support 81 and the feed dog 80 to disengage and reengage thesame with the upper surface of the work.

In operation the downward movement of the upper feed dog is timed tocorrespond with the upward movement of the lower feed dog so that thetwo feed dogs will approach and simultaneously engage the oppositesurfaces of the work. The forward movement of the lower feed dogheretofore described will cause the upper feed cog to be carried with ituntil it reaches the eX- tremity of its forward movement whereupon theoperation of the cam 95 will cause the upper feed dog to be releasedfrom the work and simultaneously therewith the lower feed dog will bedepressed from its engagement with the lower surface of the work. Uponbeing released the upper feed dog is permitted to return to its originalposition preparatory to engagement for the next forward movement. It maydesirably be assisted in the return action by a light spring 96 securedto a stud 97 upon the feed dog supporting arm 81 and to a stud 98projecting from the segmental front plate.

A suitable bender mechanism is illustrated in Figs. 2 and 3 which isadapted to cooperate with the stitch forming mechanism in forming a rowof stitches in the lower or base layer of fabric but inasmuch as thisforms no part of the present invention, and is included in the companionapplication above referred to, it need not be specifically describedherein.

It is to be understood that the embodiment disclosed herein isillustrative merely but is not restrictive and that this invention maybe embodied in other specific forms and that the following claims areintended to cover equivalent mechanical structural features andcombinations.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. Feeding mechanism for sewing machines comprising a work support, afeed dog, toggle mechanism connected to said work support and said feeddog adapted to cause relative movement between said feed dog and saidwork support alternately to raise and lower said work support and feeddog into engagement with the under surface of the work, means foractuating the same and means actuated intermediate of the raising andlowering of said feed dog automatically to advance and to retract saiddog.

2. Feeding mechanism for sewing machines comprising a reciprocable worksupport, an under feed dog movable relatively thereto, toggle mechanismconnecting said work support and said feed dog to cause relative up anddown movement therebetween, means for actuating said toggle, and meansactuated intermediate of successive movements of the feed dogalternately to advance and to retract said dog.

Feeding mechanism for sewing machines comprising a reciprocable worksupport, an under feed dog movable relatively thereto toggle mechanlsmconnecting said work support and said feed dog to cause relative up anddown movement therebetween, means for actuating said toggle, meansactuated intermediate of said move ments of the feed dog alternately toad-' vance and to retract said dog, an upper feed dog and means forcausing the same to clamp the work against the lower feed dog and topartake of the advancing movement of the lower feed dog.

4:. Feed mechanism for a sewing machine comprising a reciprocable worksupport, a feed dog pivotally and slidably mounted thereon, a togglemechanism connecting said feed dog and said work support, means foractuating said toggle mechanism to cause said work support and said dogalternately to engage the goods and means for advancing and retractingsaid dog.

5. Feeding mechanism for sewing machines comprising a work support and afeed dog pivotally and slidably mounted there on, a rock shaft, meansconnecting the pivotal support for said feed dog to said rock shaft tocause forward and backward movement thereof, toggle mechanism connectingsaid work support and said feed dog adapted to raise and lower saidsupport and dog alternately, a rocking sleeve mounted upon said rockshaft, means connecting said sleeve to said toggle and means foractuating said rock shaft and said sleeve.

6. Feeding mechanism for sewing machines comprising a work support, afeed dog pivotally and slidably mounted thereon, a rock shaft, meansconnecting the pivotal support for said feed dog to said rock shaft tocause forward and backward movement thereof, toggle mechanism connectingsaid work support and said feed dog adapted to raise and lower saidsupport and dog alternately, a rocking sleeve mounted upon said rockshaft, means for actuating said sleeve and said rock shaft, and meansfor adjustin the amplitude of vibration of the latter.

chines comprising a work support and feed dog pivotally and slidablymounted thereon, a rock shaft, means connecting the pivotal support forsaid feed dog to said rock shaft to cause forward and backward movementthereof, toggle mechanism connecting said work support and said feed dogadapted to raise and lower said support and dog alternately, a rockingsleeve mounted upon said rock shaft, means for actuating said sleeve andsaid rock shaft, and means for adjusting the amplitude of vibration ofthe latter com prising a floating lever, a cam for vibrating the sameand a fulcrum for said lever adjustable relative to the axis thereof tovary its longitudinal movement.

8. Feeding mechanism for sewing machines comprising a work support, afeed dog slidably mounted thereon, means for reciprocating said feed dogin a plane parallel to the work supporting surface of the work supportto advance and retract the same comprising an extensible lever pivotallymounted on said work support and con nected to said feed dog, means foroscillating said lever, and means for raising and lowering said feed dogrelative to the surface of said work support.

9. Feeding mechanism for sewing machines comprising a work support, afeed dog slidably mounted therein, means for reciprocating said feed dogto advance and retract the same comprising an extensible lever pivotallymounted on said work support and connected to said feed dog, means foroscillating said lever, toggle mechanism for raising and lowering saidfeed dog relative to the work support and meansfor actuating saidtoggle.

10. Feeding mechanism for sewing machines comprising a yielda-blymounted work support having a vertical guideway, a feed dog supportingstand slidably mounted in said guideway and having a horizontalguideway, a feed dog mounted in said h0rizontal guideway, means forcausing relative movement between the work support and the feed dogsupporting stand to cause said work support and feed dog alternately toengage the work and means for advancing and retracting the feed (10 11.Feeding mechanism for sewing ma chines comprising a yieldably mountedwork support having a vertically depending sleeve, a feed dog supportingstand comprising a stem slidably mounted in said sleeve, a horizontalguideway in said feed dog supporting stand, a feed dog mounted in saidguideway, a toggle connecting the work support and said stem and meansfor actuating said toggle whereby the work support and feed dog willalternately be raised into engagement with the work and means forreciprocating said feed dog.

12. Feeding mechanism for sewing machines comprising a yieldably mountedwork support having a vertically depending sleeve, a feed dog supportingstand comprising a stem slidably mounted in said sleeve, a horizontalguideway in said feed dog supporting stand, a feed dog mounted in saidguideway, a toggle connecting the work support and said stem and meansfor actuating said toggle whereby the work support and feed dog willalternately be raised. into engagement with the work and means forreciprocating said feed dog, comprising a bell crank lever supportedupon said stem, one arm of said lever having a telescopically extensibleconnection with said feed dog.

13. Feeding mechanisms for sewing machines comprising a yieldablymounted work support having a depending sleeve, a feed dog' supportingstand having a stem slidably mounted in said sleeve, a horizontalguideway upon said stand, a feed dog support having a depending earslidably mounted in said guideway, a cross-head connected to said stem,a toggle connected to said cross head and said work support, and meansfor actuating the same, a bell crank lever mounted upon said cross headone arm of said lever having a guideway, a member pivotally mounted uponthe ear of said feed dog support and having a stem slidably mounted insaid guideway and means for actuating said bell crank lever.

14. Feeding mechanisms for sewing machines comprising a feed dogsupporting stand, a feed dog support slidably mounted thereon having ahorizontal web, and downwardly extending ribs spaced. apart to form achannel, a member secured to said stand and projecting into said channelto form a guideway for said feed dog support, a feed dog connected tosaid support comprising extended parallel serrated work engaging facesand a short intermediate serrated work engaging face, means foractuating said feed dog supporting stand to raise and lower said feeddog and means to impart forward and backward movement to said feed dog.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

THOMAS J. HAYES. Witnesses:

FREDERICK A. TENNANT, THOMAS J. DRUMMOND.

Copies of this patent may be obtained for five cents each, by addressingthe Gommissioner of Patents,

Washington, D. G. I

